Dental handpieces are used to remove decay, prepare teeth for restorations, polish teeth and restorations, and trim dental appliances. They come in high-speed and low-speed varieties and can be straight, contra-angle, or right-angle styles. High-speed handpieces rotate at over 450,000 RPM to cut tooth structure while low-speed are used for polishing at up to 30,000 RPM. Proper maintenance like flushing, scrubbing, and lubrication according to the manufacturer is important to sterilize handpieces between patients. Air abrasion units and microetchers are also used to prepare teeth for procedures like sealants.

1. Dental Handpieces
CHAPTER 18*

2. Dental Handpieces
Used for the following:
Remove dental decay
Prepare tooth for restoration
Polish
Polish and finish dental restorations
Cut, finish, and polish dental appliances
Trim models and trays

3. Parts of the Dental Handpiece
 Working end-where the burs, discs, stones, and other rotary
instruments and attachments are held (chuck)
The bur is placed in the chuck on the handpiece
Head
 Shank- the handle portion
 Connection end-Forward and reverse controls may be located
on the connection end
The part of the handpiece that attaches to the power source

4. Dental Handpieces
 High-speed
 Low-speed
Straight
Nose cone
Contra-angle
Latch-type or friction
grip
Right angle or prophy
angle
 Electric

7. High-Speed Handpiece
 Used to rapidly cut tooth structure and finish restorations
 Operate at up to 450,000 revolutions per minute (RPM) and higher
 A smooth, one-piece design, usually a contra-angle (attachment head) with the
head slightly angled to the shank of the handpiece
 Does not hold any attachments
 Holds burs and other rotary instruments with the head of the handpiece in a small, metal
cylinder called a chuck
 Holds burs with a friction-grip shank
 To tighten or loosen the chuck, either a bur tooth/wrench or a button/release
lever on the back of the head of the handpiece is used
 the manufacturer provides the specific tool used with the handpiece, so they are packaged
TOGETHER

8. High-Speed Handpiece
 The power source for the dental handpiece comes from the
dental unit
Compressed air drives the turbines in the handpiece
To activate and control the speed, a rheostat (foot control) is operated, (like
the accelerator on a car)
 Available with fiber-optic light source
Improves visibility of the tx area for operator
The fiber-optic light is carried along optical bundles in the tubing
of the handpiece

9. High-Speed handpiece
 High–speed handpieces can
produce frictional heat, which can
cause pulpal damage to the tooth.
 It is important to use a coolant,
such as air, water, or and air-water
spray to reduce the frictional heat.

10. High-Speed Handpiece with bur tool
(chuck)

11. High-speed handpiece with push button
back

12. Low-Speed Handpiece
 Low-speed handpieces are used in
both the dental office and laboratory.
 Its uses in the dental office are to
polish teeth and restorations, remove
soft carious material, and define cavity
margins and walls.
 Usually do not have water supply
 Operate at up to 30,000 RPM

13. Low-Speed
• A little bulkier than high-
speed
• Used with long-shank
(straight) rotary instruments,
contra-angle attachments,
and right-angle attachments

14. Low-Speed Handpiece
 Contra-angles are usually latch type
 Holds burs, discs, stones, rubber cups and brushes for intraoral and
extraoral procedures
 Right-angles or prophy angles are used to polish the teeth
with rubber cups or brushes
 Straight handpiece is used with long, straight shank rotary
instruments
Burs, discs and stones with attachment heads such as contra-angle
and right angles.

16. Low-Speed Handpiece
 On the shank of the low-speed is a mechanism to lock the
rotary instrument or the attachment onto the handpiece
Could be a tightening knob, or snap-on apparatus
 Reverse and forward control is also found on the shank near
the connecting end
 The power source for low-speed is the rheostat

18. Electric Handpiece
 Electric handpieces are an alternative to
the air-driven handpiece.
 They are more versatile and used more
commonly today, allowing for smoother
cuts and refined margins with higher
torque and precision.
 The electric handpieces are becoming
more popular than the air-driven
handpieces.
 The appeal of the electric handpiece is
that it is quiet, vibration-free, efficient,
and able to be sterilized.

19. Maintenance and Sterilization of
Dental Handpieces
Maintenance
Follow manufacturer’s directions
carefully

20. Guidelines
 General guidelines for maintenance and sterilization of a
dental handpiece are as follows:
 While handpiece is still attached to the tubing and a bur,
flush for 20 to 30 seconds.
 Remove debris by scrubbing the handpiece.
 Lubricate using the manufacturer’s suggested lubrication.
 Sterilize the handpiece.
 Lubricate if instructed.

21. Air Abrasion Unit and Microetcher
 Air abrasion
 Reduces use of anesthetics and drilling with dental handpieces
 Microetcher
 Smaller version of air abrasion unit used for intraoral sandblasting and dentin bonding
 Used for denture repairs, pit and fissure sealant preparation, and roughening the surface for
bonding orthodontic bands
 When using the Microetcher, the dentist, assistant and patient should wear protective
eyewear, and the dentist and assistant should wear a mask
 Both units require air pressure and an abrasive material.
 Abrasives used in the microetcher should be kept in a tightly sealed container to
keep them dry and clean.
 It is important to consider safety for all involved while using a microetcher.

22. Microetcher, lab

23. Microetcher, intraoral